RO water

Dopesmoka

Well-Known Member
Anyone useing reverse osmosis and adding minerals back to water?? I’ve been blessed for years with great well water. Now in the city and I’m having trouble getting water dialed in.

For now I’ve been using cal mg from general organics. Which is doing the job, but it looks like now I’m getting the slightest iron, and mg deficiency on a few strains.

Anyone have a go to method for getting minerals back into filter water?
yup i use plain Ro water without ph'ing with some slow release fertilizers and i got no complaints so far.
 

green_machine_two9er

Well-Known Member
Get your water tested.

Takes all the guess work out it, and provides the relevant data needed to proceed with appropriate filtering/processing, if needed at all.

Chlorine/chloramines in irrigation water aren't a concern for use on soil with high organic matter content...
I have the city’s water test, I’m not able to make much since our it tbh. Not sure how much of a difference testing out of the faucet would be. My house is 110+ years so potentially some nasty heavy metals somewhere along the way.
 

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waktoo

Well-Known Member
I have the city’s water test, I’m not able to make much since our it tbh. Not sure how much of a difference testing out of the faucet would be. My house is 110+ years so potentially some nasty heavy metals somewhere along the way.
Usually the tests done by municipal water suppliers aren't focused on soluble mineral nutrients that affect the chemistry of soil. Yours is an example of this. They're typically geared towards providing information centered around the chemicals that adversely affect human health, which seep into water sheds and containment systems.

I'm referring to something like this...

 

Southerner

Well-Known Member
The amount of chlorine is negligable and would consider RO highly wasteful for an grow that isnt encountering specific issues with your source.
 

SupraSPL

Well-Known Member
Rain water, dehumidifier condensate and R/O are all in the same boat, completely missing calmag. I use both R/O and rain water and I am grateful that we dont have city water here. In addition to fluoride, chlorine and chloramines, tap water may deliver "emerging contaminants" of primary concern are the hundreds of pharmaceuticals found in our rivers, which are not filtered out by granular activated carbon filters or sediment filters. Probably not a huge issue but R/O will filter them out if they are present and if you have a modest size grow no problem to use R/O. Rain is a great way to go, mine comes off the roof at about 5 ppm TDS.

Anyway, blackstrap molasses provides some calmag and iron but also a strong dose of K to keep in mind. You can soak R/O or rain water in pulverized dolomite lime to pick up a bit of calmag. Large amounts of plant based compost never hurts. You could also use a combination of epsom salts, gypsum and oyster shell flour in your water to get highly soluble cal and mag. 100ppm of those in your water is probably a good place to start if your soil already has gypsum, oyster shell and good compost in it.

Another option is a green leaf slurry. Soak the ground up/mashed up leaves in rain water or R/O and they will pick up a steady release of many nutrients from the leaves. Plants and soil microbes really seem to love that in my experience.
 

smokin away

Well-Known Member
Rain water, dehumidifier condensate and R/O are all in the same boat, completely missing calmag. I use both R/O and rain water and I am grateful that we dont have city water here. In addition to fluoride, chlorine and chloramines, tap water may deliver "emerging contaminants" of primary concern are the hundreds of pharmaceuticals found in our rivers, which are not filtered out by granular activated carbon filters or sediment filters. Probably not a huge issue but R/O will filter them out if they are present and if you have a modest size grow no problem to use R/O. Rain is a great way to go, mine comes off the roof at about 5 ppm TDS.

Anyway, blackstrap molasses provides some calmag and iron but also a strong dose of K to keep in mind. You can soak R/O or rain water in pulverized dolomite lime to pick up a bit of calmag. Large amounts of plant based compost never hurts. You could also use a combination of epsom salts, gypsum and oyster shell flour in your water to get highly soluble cal and mag. 100ppm of those in your water is probably a good place to start if your soil already has gypsum, oyster shell and good compost in it.

Another option is a green leaf slurry. Soak the ground up/mashed up leaves in rain water or R/O and they will pick up a steady release of many nutrients from the leaves. Plants and soil microbes really seem to love that in my experience.
I have noticed here in southern US that rain water has a 6.7pH. I use a measuring cup under the gutter spout and fill jugs.
 

rkmcdon

Well-Known Member
I switched from ro to just filtered water and let the water sit a couple of days in 55 gallon barrels. When i first made this switch i continued to use cal-mag but i beefed up my soil (basalt, gypsum, oyster shell) and I activate it and let it sit for 3-4 weeks before using it to give the bacteria time to start mobilizing nutrients. Once I had this process in place I stopped adding cal-mag and just use the filtered water. So far, so good, but this is a recent change, so the final verdict is still out. I think if you're on the second cycle of a no-till it should be fine, but I'm on my first.
 

green_machine_two9er

Well-Known Member
I switched from ro to just filtered water and let the water sit a couple of days in 55 gallon barrels. When i first made this switch i continued to use cal-mag but i beefed up my soil (basalt, gypsum, oyster shell) and I activate it and let it sit for 3-4 weeks before using it to give the bacteria time to start mobilizing nutrients. Once I had this process in place I stopped adding cal-mag and just use the filtered water. So far, so good, but this is a recent change, so the final verdict is still out. I think if you're on the second cycle of a no-till it should be fine, but I'm on my first.
I have a couple no till pots that seem to be right in point. It’s the Second run recycled soil in 10G pots that are giving me some signs of struggle.
 

green_machine_two9er

Well-Known Member
Well I have found an artisanal well nearby my house. Runs year round and the public is able to collect drinking water from it. I’m ready to pull up my trailer and load up for the month stop messing with water all together.
 

waktoo

Well-Known Member
Well I have found an artisanal well nearby my house. Runs year round and the public is able to collect drinking water from it. I’m ready to pull up my trailer and load up for the month stop messing with water all together.
Hate to be a Debbie downer, but well water is usually worse than tap when it comes to dissolved solid content...

Get your water tested.

Takes all the guess work out it, and provides the relevant data needed to proceed with appropriate filtering/processing, if needed at all.

Chlorine/chloramines in irrigation water aren't a concern for use on soil with high organic matter content...
 
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